/* ----------------------------------------------------------------------
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
*
* $Date:        19. March 2015
* $Revision: 	V.1.4.5
*
* Project: 	    CMSIS DSP Library
* Title:	    arm_cfft_radix2_init_q31.c
*
* Description:	Radix-2 Decimation in Frequency Fixed-point CFFT & CIFFT Initialization function
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*   - Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in
*     the documentation and/or other materials provided with the
*     distribution.
*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* -------------------------------------------------------------------- */


#include "arm_math.h"
#include "arm_common_tables.h"

/**
 * @ingroup groupTransforms
 */

/**
 * @addtogroup ComplexFFT
 * @{
 */


/**
*
* @brief  Initialization function for the Q31 CFFT/CIFFT.
* @deprecated Do not use this function.  It has been superseded by \ref arm_cfft_q31 and will be removed
* @param[in,out] *S             points to an instance of the Q31 CFFT/CIFFT structure.
* @param[in]     fftLen         length of the FFT.
* @param[in]     ifftFlag       flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
* @param[in]     bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
* @return        The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
*
* \par Description:
* \par
* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
* Set(=1) ifftFlag for calculation of CIFFT otherwise  CFFT is calculated
* \par
* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
* \par
* The parameter <code>fftLen</code>	Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
* \par
* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
*/

arm_status arm_cfft_radix2_init_q31(
    arm_cfft_radix2_instance_q31 *S,
    uint16_t fftLen,
    uint8_t ifftFlag,
    uint8_t bitReverseFlag)
{
    /*  Initialise the default arm status */
    arm_status status = ARM_MATH_SUCCESS;

    /*  Initialise the FFT length */
    S->fftLen = fftLen;

    /*  Initialise the Twiddle coefficient pointer */
    S->pTwiddle = (q31_t *) twiddleCoef_4096_q31;
    /*  Initialise the Flag for selection of CFFT or CIFFT */
    S->ifftFlag = ifftFlag;
    /*  Initialise the Flag for calculation Bit reversal or not */
    S->bitReverseFlag = bitReverseFlag;

    /*  Initializations of Instance structure depending on the FFT length */
    switch (S->fftLen)
    {
        /*  Initializations of structure parameters for 4096 point FFT */
    case 4096u:
        /*  Initialise the twiddle coef modifier value */
        S->twidCoefModifier = 1u;
        /*  Initialise the bit reversal table modifier */
        S->bitRevFactor = 1u;
        /*  Initialise the bit reversal table pointer */
        S->pBitRevTable = (uint16_t *) armBitRevTable;
        break;

        /*  Initializations of structure parameters for 2048 point FFT */
    case 2048u:
        /*  Initialise the twiddle coef modifier value */
        S->twidCoefModifier = 2u;
        /*  Initialise the bit reversal table modifier */
        S->bitRevFactor = 2u;
        /*  Initialise the bit reversal table pointer */
        S->pBitRevTable = (uint16_t *) & armBitRevTable[1];
        break;

        /*  Initializations of structure parameters for 1024 point FFT */
    case 1024u:
        /*  Initialise the twiddle coef modifier value */
        S->twidCoefModifier = 4u;
        /*  Initialise the bit reversal table modifier */
        S->bitRevFactor = 4u;
        /*  Initialise the bit reversal table pointer */
        S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
        break;

        /*  Initializations of structure parameters for 512 point FFT */
    case 512u:
        /*  Initialise the twiddle coef modifier value */
        S->twidCoefModifier = 8u;
        /*  Initialise the bit reversal table modifier */
        S->bitRevFactor = 8u;
        /*  Initialise the bit reversal table pointer */
        S->pBitRevTable = (uint16_t *) & armBitRevTable[7];
        break;

    case 256u:
        /*  Initializations of structure parameters for 256 point FFT */
        S->twidCoefModifier = 16u;
        S->bitRevFactor = 16u;
        S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
        break;

    case 128u:
        /*  Initializations of structure parameters for 128 point FFT */
        S->twidCoefModifier = 32u;
        S->bitRevFactor = 32u;
        S->pBitRevTable = (uint16_t *) & armBitRevTable[31];
        break;

    case 64u:
        /*  Initializations of structure parameters for 64 point FFT */
        S->twidCoefModifier = 64u;
        S->bitRevFactor = 64u;
        S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
        break;

    case 32u:
        /*  Initializations of structure parameters for 32 point FFT */
        S->twidCoefModifier = 128u;
        S->bitRevFactor = 128u;
        S->pBitRevTable = (uint16_t *) & armBitRevTable[127];
        break;

    case 16u:
        /*  Initializations of structure parameters for 16 point FFT */
        S->twidCoefModifier = 256u;
        S->bitRevFactor = 256u;
        S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
        break;


    default:
        /*  Reporting argument error if fftSize is not valid value */
        status = ARM_MATH_ARGUMENT_ERROR;
        break;
    }

    return (status);
}

/**
 * @} end of ComplexFFT group
 */
